Mac display dimming and brightening

macmaniac

Hi folks,
Please help. The display on my 2017 MBP(13.6.7) is dimming and brightening(10-15%) every 1 to 2 seconds when an app is active, sometimes with noticeable vertical lines. Just prior to this happening I removed two pics which were alternating/rotating as desktop background wallpaper; related? It does not do this while cursor is moving or when only the desktop is on screen. Thank you.

Marvin

macmaniac said:

Hi folks,
Please help. The display on my 2017 MBP(13.6.7) is dimming and brightening(10-15%) every 1 to 2 seconds when an app is active, sometimes with noticeable vertical lines. Just prior to this happening I removed two pics which were alternating/rotating as desktop background wallpaper; related? It does not do this while cursor is moving or when only the desktop is on screen. Thank you.

Sometimes visuals can mess up like this if the graphics chip goes bad. If you have a 15" model, they have two GPUs and one can go bad so you get artifacts when it switches to the bad GPU.

Brightness issues can be due to a bad display cable or backlight. Check if the lines change when rotating the display.

If you boot into safe mode (hold shift-key when booting), check if it does the same.